https://petition.parliament.uk/petitions/728017

The "rejection text" includes a link to the Electoral Commission, which includes this section...

Motivational mindsets

• Application of the COM-B behavioural framework highlights that the primary barrier or enabler to registration is motivational.
• The research has observed three motivational mindsets which act as the primary building block in registration behaviour. Two of these are barrier mindsets and include disillusionment in the political system or politicians, and apathy towards voting.
• The third is an enabling mindset focusing on engagement in having your say or voice heard. The research suggests that there are a range of motivational, capability-based and opportunity-based hooks which could encourage registration across these mindsets.

It's nonetheless very kind of HM Govt. to point us to the Electoral Commission's report on Attitudes to Voter Registration.  

Too bad HM Gov didn't notice that page 26 puts it quite clearly: "participants expressing apathy included those who described a disconnection with the value of their vote. These participants were sometimes unsure that their vote would make a difference in an election which further reinforced a disconnect with the need to register to vote. Building the belief that having your say is important could help encourage greater engagement in having your say and therefore registration."

Well who would have thought it? Oh, wait... no, actually, we've all thought it for years, haven't we! 😲  And if this disconnect de-motivates people from registering to vote, then just maybe, it could stop already-registered voters from voting too?